Content containing two-dimensional (2D) images has mainly been used as broadcast content until now from the analog broadcast era even though digital broadcasts are currently active. In recent years, content containing three-dimensional (3D) images (or stereoscopic images) providing realism and a stereoscopic effect has been increasingly used in a specific field of application, as compared with planar 2D images.
By reflecting such a trend, people's interest in 3D image display that is capable of providing 3D image content has increased, and devices for 3D image display have spread to households in recent years.
3D images allow users to experience 3D effects using the principle of stereo vision which provides a sense of perspective through different views of the two eyes which are separated by about 65 mm, i.e. through binocular parallax due to the distance between the two eyes. To this end, the 3D images are provided such that corresponding planar images are viewed with the left and right eyes, thereby allowing the users to experience 3D and perspective effects.
However, the 3D images may not substitute for 2D images but the 3D images and the 2D images may coexist due to characteristics of content or services, although analog broadcasting is completely replaced by digital broadcasting.